1. Field of Invention
This invention is related to the countertop small manually operated fluid dispensers used for hand creams, lotions, soaps, etc. commonly found in household kitchens, bathrooms, and laundry rooms.
2. Prior Art
Most of these dispensers are of the type where a spout, mounted on the cap of a bottle containing fluid, is depressed by the thumb and a relatively small quantity of fluid from the bottle is dispensed through the spout into the fingers of the same hand; that is, a one handed manual dispenser. Fluids include soap, hand cream, and skin lotion. Some of these devices are used to dispense food condiments such as mustard, ketchup, mayonnaise, etc. In this case, the fluid is commonly dispensed directly onto food, onto a plate of food, or on a side dish. These dispensers have been very popular because they are less messy and more sanitary than removing fluid by squeezing a tube, by dipping an opened jar with serving utensils or with fingers (cold cream for example).
Typical examples of today's dispensers are found in U.S. Pat. Nos. 6,488,185 to Beranger et al, and 6,929,156 to Petit et al. This is based on inspection of dozens of popular dispensers sold today. These modern dispensers are very complex requiring 12 to 15 precision parts for a pump using a piston/cylinder system, at least two check valves, and a means of venting the bottle to prevent a vacuum from forming in the bottle as the volume of fluid is removed. These pumps are becoming prohibitively expensive and these dispensers can add up to 30% to the price of the fluid. Many fluids are now offered in either a pump dispenser (for a few dollars more) or a cheaper squeeze tube.
Because these pumps and valves are placed just under the cap of the fluid container, the output check valve is far from the end of the spout and fluid is always left in the spout to dry out, or to become contaminated with germs in the case of multiple users. The fluid will also run out of the spout if the bottle is tipped. In addition, this pump must suck fluid through a tube that has its open end near the bottom of the bottle. This leaves the user having to throw out (or bottom fish for) the last ounce of fluid. In other words, the suction is lost when the pump starts to suck air when the bottle is not completely empty.
The U.S. Pat. Nos. 2,702,147 to Brown (1955) and 3,409,184 to Stengle (1968) use a different type of pump than the piston/cylinder pump. The pumps of both patents use a collapsible volume (diaphragm) at the bottom of the fluid bottle that pushes rather than sucks the fluid through to the top spout. Unfortunately Brown's dispenser, which is fully integrated into the fluid bottle, is as complex as today's dispensers. This integration would clearly limit the bottle style. Precision parts are still required for sealing the collapsible volume into the bottom of the bottle, and two check valves are required. The spout and tube are left filled with fluid that can dry and clog the spout. The fluid will also spill out if the bottle is tipped. The long thin channel required to input fluid to the diaphragm would delay the reset of the diaphragm as it expands back into natural shape and would be problematic for more viscous fluids like lotions or creams. This wait time would frustrate the user. The flexing of the hemispherical thick-walled diaphragm is rather extreme, which would prematurely tear or rupture over time. The design of the diaphragm is critical (especially if the properties change with time), because if it does not reset, the pump will fail. In all, this dispenser offers no advantage over current dispensers.
Stengle's device (U.S. Pat. No. 3,409,184) has the simplicity we are looking for, but unfortunately it does not have the quality of today's dispenser. Stengle uses a bellows for the collapsible volume with holes at the bottom pleat to introduce the fluid into the bellows. The holes are closed against the bottom of the bottle when the bellows begins to expand (reset) and wide open when the bellows starts to compress (when the spout is pushed down). This is 180 degrees out of phase for an efficient pump. Most of the fluid will move out of the holes rather than up the connecting tube/spout when the bellows is compressed, and the fluid cannot easily move into the bellows until the bellows expands. The long wait time for the bellows to reset would be similar to Brown's U.S. Pat. No. (2,702,147). The volume of fluid dispensed (if any) would depend on how fast the user compresses the bellows. Because the fluid in the connecting tube and spout drains back into the bellows between dispensing, drying in the spout is not an issue unless the fluid is viscous. But the user must re-fill the tube and spout volumes with each compression of the bellow before fluid exits the spout, which results in a significant delay before the fluid is dispensed. This also means the volume dispensed would depend on the height of the fluid level in the fluid bottle. Venting of the bottle is done through the spout which will partially fill the bellows with air, thus making the pump even less efficient. Fluid will also run out if the bottle is tipped. In addition, from Applicants' experience, without the diaphragm/bellows being integrated to the bottom of the bottle, the bellows will slide around and tip the spout in different directions. In all, this dispenser would be considered to be of poor quality by the user.